Host Info

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already mark readOnly/openWorld/idempotent/non-destructive. The description adds substantial behavior beyond that: substring matching may return several hosts, each with its own services; a configured-but-unmonitored host returns monitored:false with no check results; a non-existent host raises. This is exactly the kind of nuance the agent needs.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three short paragraphs, each with a job: core purpose, matching/alternative, edge case. No filler, and the most decision-relevant fact (substring match) is front-loaded.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With a single well-documented parameter, an output schema present, and annotations covering safety/idempotence, the description covers matching behavior, alternatives, and error semantics. Nothing needed for correct invocation is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so baseline is 3, but the description adds important parameter behavior: hostname matches as a substring and can return multiple hosts. This is valuable, though it slightly conflicts with the schema's 'Exact host name' wording, which is why it doesn't get a 5.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Opens with a specific verb-resource pair: 'Detailed status of a host plus the services running on it.' It immediately differentiates from list_services_by_state by stating what this tool is not (estate-wide failure view), so an agent can select it correctly.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly says to use list_services_by_state instead when wanting failing services across the whole estate, and the input schema reinforces that hostname is required and there is no estate-wide form. It also points to sibling tools for obtaining a valid name.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.